As many others here have pointed out, we stumble upon a fundamental issue with blockchains here. The thing that's inside the blockchain can be verified but as long as it points to something in the physical world or to be more precise, outside the chain, you have a weak link. People can ignore to respect the NFT, or simply choose to reject it. Tokens in themselves have no intrinsic value, unlike a painting, a commodity (like gold or even uranium). Of course, there is one exception to this; money. That's why bitcoin was a slightly better idea (but it suffers from different problems in my opinion). The ultimate conclusion for me at least is this one, ownership, art, justice (legal blockchains, smart contracts), these are all social problems and they cannot be solved with mere technology. Technology may help of course, but in the end I strongly believe that social problems require social solutions, not technical ones. For instance, consider bitcoin, with a 51% attack you could gain control over the chain, with PoS big stakers have control, this means you just traded the bankers of today with some other bankers. In the case of NFT, you could have a token that indicates you're the owner of a painting, but if that painting is stolen and sold by people who don't care about your NFT, what's the point? Stealing, in this case is a social problem, not a technological one.